Complete Form W-4 so that your employer can withhold the correct federal income tax from your pay. Give Form W-4 to your employer.Complete Form W4 so that your employer can withhold the correct federal income tax from your pay. Consider completing a new Form W-4 each year. How to fill out tax form W4 Employee Withholding Certificate. The forms below may be printed out and used for requests through eFile Texas. Attorneys should use this Service Request Form as the lead document.